Key Areas

 

The compositions of such contemporary jazz artists as Chick Corea, Wayne Shorter, Pat Metheny, Yellowjackets, and others represent an expansion of earlier harmonic concepts in jazz composition. The use of nondiatonic and nonfunctional harmonies makes this music more difficult to analyze than traditional jazz tunes. A desire to teach and write music in this style led me to search for new ways to justify and analyze contemporary jazz harmonic concepts. An approach that I've explored involves analysis according to the key areas within a given piece. 

 

I found it convenient to group the key area analyses into three categories: established, implied, and ambiguous key areas. Often, contemporary jazz composers combine elements of all three within a single composition. Each type of key area has a specific effect on the listener. A main difference between each key area type is root motion between chords. The established key approach utilizes a lot of cycle-five root motion, creating a sense of predictability and a strong forward momentum. Root motion found in the implied and ambiguous key areas involves smaller steps and is therefore less predictable, creating less forward momentum. Smaller root motion between adjacent chords combined with specific treatment of the harmony and melody can produce a progression that is fresh sounding and full of surprises. What follows is an introduction to harmonic analysis using established, implied, and ambiguous key areas.

Established Key

In an established key area, there is no doubt as to what the key is. The key becomes established through the use of a number of "grounding" elements, including diatonic melody, diatonic and diatonically related chords, harmonic rhythm, harmonic and melodic phrases, cadential patterns, and resolution to a tonic I chord. In an established key area, possibly the strongest grounding element is root motion down a perfect fifth (cycle-five root motion). This type of movement not only creates a feeling of strong forward harmonic motion throughout a progression; it also produces the most common contiguous chordal relationship known as the II-V pattern. If we look for typical grounding elements, it should be possible to determine the established key without actually playing or hearing the music. Musical example 1 incorporates many of the grounding elements necessary to create an established key area. 

Implied Key
The second type is the implied key area, in which the key is established through the use of diatonic and diatonically related chords. The main difference between established and implied key areas is that there is never a cadence to a tonic I chord. It should be possible to feel the key area and even sing the solfege syllable "do" when a tune ends. With this type of progression, though, the key is often difficult to determine because of the absence of a I chord. In order to avoid tonicizing the progression, it is common to resolve to an inversion of the I chord or to use the root of the I chord with a hybrid or modal interchange structure above that note to disguise the tonic quality. As mentioned previously, in implied key areas root motion does not typically follow the cycle-five patterns found in established key areas. As a result, an implied key area feels less grounded than an established key and therefore has a lighter feel of forward momentum.

In example 2, note the ascending root motion in the introduction. This is an attempt to eliminate the predictability of cycle-five root motion. Although ascending root motion is commonly associated with nonfunctional harmony, it is still possible to hear these chords functioning within the key of C major. 

Ambiguous Key
In an ambiguous key area, chords progress forward without functioning or being grounded in a key. In fact, there is no key, which makes this type of progression nonfunctional. After hearing this type of progression, it should be impossible to sing the solfege syllable "do." In an ambiguous key area, the criteria for placing one chord after another can rely on adjacent chordal relationships. In other words, what precedes and/or follows a chord determines the chord's function or relative color in the context of the adjacent chords. Since they are not anchored to a key, the sense of forward harmonic motion is dependent on harmonic sequence, root motion, and adjacent chordal relationships. Criteria for determining chord scales in an established key area are usually determined by the way the in which chords function relative to the key. In an ambiguous key area, consideration of chord resolution, adjacent chordal relationships, modal color, and melodic function can help you decide which chord scales to use. 

 

In example 3, nonfunctional chords in the A section were loosely based on a 10-note tone row. Criteria for creating the row involved avoiding cycle-five root motion and tonicizing any one note in the row. After the row is in place, chords are placed on top of each note which is assigned a function as either the root, third, fifth or seventh within each chord. Experimenting with hybrids and polychord structures above each note in the row creates an ambiguous sound. Once the chords are in place, the melody is drawn from chord tones or available tensions on each chord. The B section of the tune goes to the key of c minor. The implied key area of F major is used in section C. The chord progression in section D facilitates a transition back to the top of the tune.

Conclusion
Regardless of what you are doing creatively, it is helpful to try new methods. I hope these ideas help to broaden your musical horizons.